One need to perform below mentioned steps to generate CSR Key for SSL Certificate:
1) Open IIS Manager.
2) Click on the websites.
3) Right click on desired website for which one need to generate CSR Key.
4) Select Properties.
5) Select Directory Security Tab.
6) Click on server certificates.
7) Click on next.
8) Click on create a new certificate -> Click Next.
9) Prepare the request now, but send it later and click next.
10) Enter the require details
11) Enter the file name in which we need to store the Key and click next.
12) Check the details and click next and finish.